A leading academic has warned that Labour faces a split not just in its leadership, but in its core support within the electorate.
"The problem is not Jeremy Corbyn," he told talkRADIO's Julia Hartley-Brewer. "Jeremy Corbyn is a bit of a challenge, but the problem mainly, which is a problem facing all social democratic parties, is they are completely split between two groups in their electorate.
"They've got typically London-based, middle-class, highly educated professionals who embrace European integration, globalisation and immigration, but on the other hand they've got working class voters who think the complete opposite.
"Labour is facing two challenges: one is from UKIP and the other is from political apathy," he added. "The one time [voters] had an opportunity to feed back into politics at the referendum, they turned out in massive numbers against immigration in Europe. This is a real challenge for Labour – I would not even say it's a crisis, I would say it's a existential crisis for the Labour party."
Many have seen Leave winning the referendum as a victory for UKIP, despite Nigel Farage's party having campaigned separately to the official Leave group of MPs. And with immigration being a key issue for many voters and Leave-supporting MPs now backtracking on promises to reduce migrant numbers, Professor Goodwin says that parties such as UKIP are here to stay.
"[Immigration is] primarily is why UKIP were able to put together a very successful coalition between 2010-2014, and why they were able to contribute to the Brexit victory, but it now means if the Eurosceptics who are in charge of a Brexit Britain do not deliver on controlling immigration, there will always be a place for a party like UKIP."
More than three and a half million people have signed a petition for a second referendum, but Goodwin does not believe that will materialise.
"I think now that we've voted for Brexit, this is what we're going to be dealing with for the immediate future. I do not think the second referendum will get any traction.
"The only way forward, possibly, is if somebody perhaps wins the general election at the end of the year or early next year and has campaigned explicitly for a second referendum, but that's distinctly unlikely.
"Potentially the Liberal Democrats are in an interesting place – they've already said that a second referendum will be in their manifesto. But I still think there's a leadership question with the Liberal Democrats – I still l think they're going to struggle to put together a decent coalition."